IMMIGRATION is the international movement of people into a
destination country of which they are not natives or where they do not
possess citizenship in order to settle or reside there, especially as
permanent residents or naturalized citizens, or to take-up employment
as a migrant worker or temporarily as a foreign worker .

As for economic effects, research suggests that migration is
beneficial both to the receiving and sending countries. Research, with
few exceptions, finds that immigration on average has positive
economic effects on the native population, but is mixed as to whether
low-skilled immigration adversely affects low-skilled natives. Studies
show that the elimination of barriers to migration would have profound
effects on world GDP, with estimates of gains ranging between 67 and
147 percent. Development economists argue that reducing barriers to
labor mobility between developing countries and developed countries
would be one of the most efficient tools of poverty reduction.

The academic literature provides mixed findings for the relationship
between immigration and crime worldwide, but finds for the United
States that immigration either has no impact on the crime rate or that
it reduces the crime rate. Research shows that country of origin
matters for speed and depth of immigrant assimilation, but that there
is considerable assimilation overall for both first- and
second-generation immigrants.

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Main article:
Early human migrations _ Sign Immigration_ near
the border between Mali and Mauritania; sponsored by EU

Many animals have migrated across evolutionary history (not including
seasonal bird migration ), including pre-humans . Human migration
started with the migration out of Africa into the Middle East, and
then to Asia,
Australia , Europe , Russia , and the Americas. This is
discussed in the article pre-modern human migration .

Recent history is discussed in the articles history of human
migration and human migration .

When people cross national borders during their migration, they are
called migrants or immigrants (from Latin: _migrare_, wanderer) from
the perspective of the country which they enter. From the perspective
of the country which they leave, they are called emigrant or
outmigrant.
Sociology designates immigration usually as migration (as
well as emigration accordingly outward migration).

STATISTICS

The global population of immigrants has grown since 1990 but has
remained constant at around 3% of the world's population.

As of 2015 , the number of international migrants has reached 244
million worldwide, which reflects a 41% increase since 2000. One third
of the world's international migrants are living in just 20 countries.
The largest number of international migrants live in the United States
, with 19% of the world's total.
Germany and Russia host 12 million
migrants each, taking the second and third place in countries with the
most migrants worldwide.
Saudi Arabia hosts 10 million migrants,
followed by the
United Kingdom (9 million) and the United Arab
Emirates (8 million).

Between 2000 and 2015, Asia added more international migrants than
any other major area in the world, gaining 26 million. Europe added
the second largest with about 20 million. In most parts of the world,
migration occurs between countries that are located within the same
major area.

In 2015, the number of international migrants below the age of 20
reached 37 million, while 177 million are between the ages of 20 and
64. International migrants living in Africa were the youngest, with a
median age of 29, followed by Asia (35 years), and Latin
America/Caribbean (36 years), while migrants were older in Northern
America (42 years), Europe (43 years), and Oceania (44 years).

Nearly half (43%) of all international migrants originate in Asia,
and Europe was the birthplace of the second largest number of migrants
(25%), followed by Latin America (15%).
India has the largest diaspora
in the world (16 million people), followed by Mexico (12 million) and
Russia (11 million).

2012 SURVEY

A 2012 survey by Gallup found that given the opportunity, 640 million
adults would migrate to another country, with 23% of these would-be
immigrant choosing the
United States as their desired future
residence, while 7% of respondents, representing 45 million people,
would choose the
United Kingdom . The other top desired destination
countries (those where an estimated 69 million or more adults would
like to go) were
Canada ,
France ,
Saudi Arabia ,
Australia , Germany
and
Spain .

UNDERSTANDING OF IMMIGRATION

The largest Vietnamese market in
Prague , also known as "Little
Hanoi". In 2009, there were about 70,000 Vietnamese in the Czech
Republic .
London has become multiethnic as a result of
immigration. In
London in 2008,
Black British and British Asian
children outnumbered white British children by about 3 to 2 in
government-run schools.

One theory of immigration distinguishes between push and pull
factors.

Push factors refer primarily to the motive for immigration from the
country of origin. In the case of economic migration (usually labor
migration), differentials in wage rates are common. If the value of
wages in the new country surpasses the value of wages in one's native
country, he or she may choose to migrate, as long as the costs are not
too high. Particularly in the 19th century, economic expansion of the
US increased immigrant flow, and nearly 15% of the population was
foreign born , thus making up a significant amount of the labor
force.

As transportation technology improved, travel time and costs
decreased dramatically between the 18th and early 20th century. Travel
across the Atlantic used to take up to 5 weeks in the 18th century,
but around the time of the 20th century it took a mere 8 days. When
the opportunity cost is lower, the immigration rates tend to be
higher. Escape from poverty (personal or for relatives staying
behind) is a traditional push factor, and the availability of jobs is
the related pull factor.
Natural disasters can amplify poverty-driven
migration flows. Research shows that for middle-income countries,
higher temperatures increase emigration rates to urban areas and to
other countries. For low-income countries, higher temperatures reduce
emigration.

Emigration and immigration are sometimes mandatory in a contract of
employment: religious missionaries and employees of transnational
corporations , international non-governmental organizations , and the
diplomatic service expect, by definition, to work "overseas". They are
often referred to as "expatriates ", and their conditions of
employment are typically equal to or better than those applying in the
host country (for similar work).

For some migrants, education is the primary pull factor (although
most international students are not classified as immigrants).
Retirement migration from rich countries to lower-cost countries with
better climate is a new type of international migration. Examples
include immigration of retired British citizens to
Spain or
Italy and
of retired Canadian citizens to the US (mainly to the US states of
Florida and
Texas ).

Non-economic push factors include persecution (religious and
otherwise), frequent abuse, bullying , oppression , ethnic cleansing ,
genocide , risks to civilians during war , and social marginalization.
Political motives traditionally motivate refugee flows; for
instance, people may emigrate in order to escape a dictatorship .

Some migration is for personal reasons, based on a relationship (e.g.
to be with family or a partner), such as in family reunification or
transnational marriage (especially in the instance of a gender
imbalance ). Recent research has found gender, age, and cross-cultural
differences in the ownership of the idea to immigrate. In a few
cases, an individual may wish to immigrate to a new country in a form
of transferred patriotism . Evasion of criminal justice (e.g.,
avoiding arrest ) is a personal motivation. This type of emigration
and immigration is not normally legal, if a crime is internationally
recognized, although criminals may disguise their identities or find
other loopholes to evade detection. For example, there have been
reports of war criminals disguising themselves as victims of war or
conflict and then pursuing asylum in a different country.

Barriers to immigration come not only in legal form or political
form; natural and social barriers to immigration can also be very
powerful. Immigrants when leaving their country also leave everything
familiar: their family, friends, support network, and culture. They
also need to liquidate their assets, and they incur the expense of
moving. When they arrive in a new country, this is often with many
uncertainties including finding work, where to live, new laws, new
cultural norms, language or accent issues, possible racism , and other
exclusionary behavior towards them and their family. The Iron
Curtain in Europe was designed as a means of preventing emigration .
"It is one of the ironies of post-war European history that, once the
freedom to travel for Europeans living under communist regimes, which
had long been demanded by the West, was finally granted in 1989/90,
travel was very soon afterwards made much more difficult by the West
itself, and new barriers were erected to replace the Iron Curtain."
—Anita Böcker

The politics of immigration have become increasingly associated with
other issues, such as national security and terrorism , especially in
western Europe, with the presence of
Islam as a new major religion.
Those with security concerns cite the
2005 French riots and point to
the
Jyllands-Posten Muhammad cartoons controversy as examples of the
value conflicts arising from immigration of Muslims in Western Europe
. Because of all these associations, immigration has become an
emotional political issue in many European nations.

Studies have suggested that some special interest groups lobby for
less immigration for their own group and more immigration for other
groups since they see effects of immigration, such as increased labor
competition, as detrimental when affecting their own group but
beneficial when impacting other groups. A 2010 European study
suggested that "employers are more likely to be pro-immigration than
employees, provided that immigrants are thought to compete with
employees who are already in the country. Or else, when immigrants are
thought to compete with employers rather than employees, employers are
more likely to be anti-immigration than employees." A 2011 study
examining the voting of US representatives on migration policy
suggests that "representatives from more skilled labor abundant
districts are more likely to support an open immigration policy
towards the unskilled, whereas the opposite is true for
representatives from more unskilled labor abundant districts."

Another contributing factor may be lobbying by earlier immigrants.
The Chairman for the US Irish Lobby for
Immigration Reform—which
lobby for more permissive rules for immigrants, as well as special
arrangements just for Irish people—has stated that "the Irish Lobby
will push for any special arrangement it can get—'as will every
other ethnic group in the country.'"

Immigrants are motivated to leave their former countries of
citizenship, or habitual residence, for a variety of reasons,
including a lack of local access to resources , a desire for economic
prosperity , to find or engage in paid work, to better their standard
of living , family reunification , retirement , climate or
environmentally induced migration, exile , escape from prejudice,
conflict or natural disaster, or simply the wish to change one's
quality of life . Commuters , tourists and other short-term stays in a
destination country do not fall under the definition of immigration or
migration, seasonal labour immigration is sometimes included.

ECONOMIC MIGRANT

Further information:
Economic migrant The Indo-Bangladeshi
barrier in 2007.
India is building a separation barrier along the
4,000 kilometer border with Bangladesh to prevent illegal immigration.

The term economic migrant refers to someone who has travelled from
one region to another region for the purposes of seeking employment
and an improvement in quality of life and access to resources. An
economic migrant is distinct from someone who is a refugee fleeing
persecution.

Many countries have immigration and visa restrictions that prohibit a
person entering the country for the purposes of gaining work without a
valid work visa. As a violation of a State\'s immigration laws a
person who is declared to be an economic migrant can be refused entry
into a country.

The
World Bank estimates that remittances totaled $420 billion in
2009, of which $317 billion went to developing countries.

LAWS AND ETHICS

UNHCR tents at a refugee camp following episodes of
anti-immigrant violence in South Africa, 2008 Entry (top)
and Exit (above) passport stamps issued to a citizen of
Germany by
Indian immigration authorities at New Delhi airport .

Treatment of migrants in host countries, both by governments,
employers, and original population, is a topic of continual debate and
criticism, and the violation of migrant human rights is an ongoing
crisis. The United Nations Convention on the Protection of the Rights
of All Migrant Workers and Members of Their Families , has been
ratified by 48 states, most of which are heavy exporters of cheap
labor. Major migrant-receiving countries and regions - including
Western Europe ,
North America , Pacific Asia ,
Australia , and the
Gulf States - have not ratified the Convention, even though they are
host to the majority of international migrant workers. Although
freedom of movement is often recognized as a civil right in many
documents such as the
Universal Declaration of Human Rights (1948) and
the
International Covenant on Civil and Political Rights (1966), the
freedom only applies to movement within national borders and the
ability to return to one's home state.

Some proponents of immigration argue that the freedom of movement
both within and between countries is a basic human right, and that the
restrictive immigration policies, typical of nation-states, violate
this human right of freedom of movement. Such arguments are common
among anti-state ideologies like anarchism and libertarianism . As
philosopher and Open borders activist Jacob Appel has written,
"Treating human beings differently, simply because they were born on
the opposite side of a national boundary, is hard to justify under any
mainstream philosophical, religious or ethical theory."

Where immigration is permitted, it is typically selective. As of 2003
, family reunification accounted for approximately two-thirds of legal
immigration to the US every year. Ethnic selection, such as the White
Australia policy , has generally disappeared, but priority is usually
given to the educated, skilled, and wealthy. Less privileged
individuals, including the mass of poor people in low-income
countries, cannot avail themselves of the legal and protected
immigration opportunities offered by wealthy states. This inequality
has also been criticized as conflicting with the principle of equal
opportunities . The fact that the door is closed for the unskilled,
while at the same time many developed countries have a huge demand for
unskilled labor, is a major factor in illegal immigration . The
contradictory nature of this policy—which specifically disadvantages
the unskilled immigrants while exploiting their labor—has also been
criticized on ethical grounds.

Immigration policies which selectively grant freedom of movement to
targeted individuals are intended to produce a net economic gain for
the host country. They can also mean net loss for a poor donor country
through the loss of the educated minority—a "brain drain ". This can
exacerbate the global inequality in standards of living that provided
the motivation for the individual to migrate in the first place. One
example of competition for skilled labour is active recruitment of
health workers from developing countries by developed countries.
There may however also be a "brain gain" to emigration, as migration
opportunities lead to greater investments in education in developing
countries. Overall, research suggests that migration is beneficial
both to the receiving and sending countries.

ECONOMIC EFFECTS

A survey of leading economists shows a consensus behind the view that
high-skilled immigration makes the average American better off. A
survey of the same economists also shows strong support behind the
notion that low-skilled immigration makes the average American better
off. A survey of European economists shows a consensus that freer
movement of people to live and work across borders within Europe makes
the average European better off, and strong support behind the notion
that it has not made low-skilled Europeans worse off. According to
David Card , Christian Dustmann, and Ian Preston, "most existing
studies of the economic impacts of immigration suggest these impacts
are small, and on average benefit the native population". In a survey
of the existing literature, Örn B Bodvarsson and Hendrik Van den Berg
write, "a comparison of the evidence from all the studies... makes it
clear that, with very few exceptions, there is no strong statistical
support for the view held by many members of the public, mainly that
immigration has an adverse effect on native-born workers in the
destination country."

OVERALL ECONOMIC PROSPERITY

Whereas the impact on the average native tends to be small and
positive, studies show more mixed results for low-skilled natives, but
whether the effects are positive or negative, they tend to be small
either way. Immigrants may often do types of work
that natives are largely unwilling to do, contributing to greater
economic prosperity for the economy as a whole: for instance, Mexican
migrant workers taking up manual farm work in the
United States has
close to zero effect on native employment in that occupation, which
means that the effect of Mexican workers on U.S. employment outside
farm work was therefore most likely positive, since they raised
overall economic productivity. Research indicates that immigrants are
more likely to work in risky jobs than U.S.-born workers, partly due
to differences in average characteristics, such as immigrants' lower
English language ability and educational attainment. Further, some
studies indicate that higher ethnic concentration in metropolitan
areas is positively related to the probability of self-employment of
immigrants. Competition from immigrants in a particular sector may
adversely affect wages for natives in that sector but increase wages
for natives outside of the sector; for instance, a 2017 study in
_Science_ found that "the influx of foreign-born computer scientists
since the early 1990s... increased the size of the US IT sector...
benefited consumers via lower prices and more efficient products...
raised overall worker incomes by 0.2 to 0.3% but decreased wages of
U.S. computer scientists by 2.6 to 5.1%."

Research also suggests that diversity and immigration have a net
positive effect on productivity and economic prosperity. A
study by Harvard economist Nathan Nunn, Yale economist Nancy Qian and
LSE economist Sandra Sequeira found that the Age of Mass Migration
(1850-1920) contributed to "higher incomes, higher productivity, more
innovation, and more industrialization" in the short-run and "higher
incomes, less poverty, less unemployment, higher rates of
urbanization, and greater educational attainment" in the long-run for
the United States.

Studies show that the elimination of barriers to migration would have
profound effects on world GDP, with estimates of gains ranging between
67–147.3%. Research also finds that migration leads to greater
trade in goods and services, and increases in financial flows
between the sending and receiving countries. Using 130 years of data
on historical migrations to the United States, one study finds "that a
doubling of the number of residents with ancestry from a given foreign
country relative to the mean increases by 4.2 percentage points the
probability that at least one local firm invests in that country, and
increases by 31% the number of employees at domestic recipients of FDI
from that country. The size of these effects increases with the ethnic
diversity of the local population, the geographic distance to the
origin country, and the ethno-linguistic fractionalization of the
origin country."

INEQUALITY

Overall immigration has not had much effect on native wage inequality
but low-skill immigration has been linked to greater income
inequality in the native population.

FISCAL EFFECTS

A 2011 literature review of the economic impacts of immigration found
that the net fiscal impact of migrants varies across studies but that
the most credible analyses typically find small and positive fiscal
effects on average. According to the authors, "the net social impact
of an immigrant over his or her lifetime depends substantially and in
predictable ways on the immigrant's age at arrival, education, reason
for migration, and similar". According to a 2007 literature review by
the
Congressional Budget Office , "Over the past two decades, most
efforts to estimate the fiscal impact of immigration in the United
States have concluded that, in aggregate and over the long term, tax
revenues of all types generated by immigrants—both legal and
unauthorized—exceed the cost of the services they use."

Research has shown that EU immigrants made a net positive fiscal
contribution to Denmark and the United Kingdom.

IMPACT OF REFUGEES

A 2017 survey of leading economists found that 34% of economists
agreed with the statement "The influx of refugees into Germany
beginning in the summer of 2015 will generate net economic benefits
for German citizens over the succeeding decade", whereas 38% were
uncertain and 6% disagreed. Studies of refugees' impact on native
welfare are scant but the existing literature shows mixed results
(negative, positive and no significant effects on native welfare).
A 2017 National Bureau of Economic Research paper found
that refugees to the
United States pay "$21,000 more in taxes than
they receive in benefits over their first 20 years in the U.S."
According to
University of California, Davis , labor economist
Giovanni Peri , the existing literature suggests that there are no
economic reasons why the American labor market could not easily absorb
100,000 Syrian refugees in a year.

Refugees integrate more slowly into host countries' labor markets
than labor migrants, in part due to the loss and depreciation of human
capital and credentials during the asylum procedure. Refugees tend to
do worse in economic terms than natives, even when they have the same
skills and language proficiencies of natives. For instance, a 2013
study of Germans in West-
Germany who had been displaced from Eastern
Europe during and after World
War II showed that the forced German
migrants did far worse economically than their native West-German
counterparts decades later. Second-generation forced German migrants
also did worse in economic terms than their native counterparts. A
study of refugees to the
United States found that "refugees that enter
the U.S. before age 14 graduate high school and enter college at the
same rate as natives. Refugees that enter as older teenagers have
lower attainment with much of the difference attributable to language
barriers and because many in this group are not accompanied by a
parent to the U.S." Refugees that entered the U.S. at ages 18-45,
have "much lower levels of education and poorer language skills than
natives and outcomes are initially poor with low employment, high
welfare use and low earnings." But the authors of the study find that
"outcomes improve considerably as refugees age."

IMPACT OF UNDOCUMENTED IMMIGRANTS

Research on the economic effects of undocumented immigrants is scant
but existing studies suggests that the effects are positive for the
native population, and public coffers. A 2015 study shows that
"increasing deportation rates and tightening border control weakens
low-skilled labor markets, increasing unemployment of native
low-skilled workers. Legalization, instead, decreases the unemployment
rate of low-skilled natives and increases income per native." Studies
show that legalization of undocumented immigrants would boost the U.S.
economy; a 2013 study found that granting legal status to undocumented
immigrants would raise their incomes by a quarter (increasing U.S. GDP
by approximately $1.4 trillion over a ten-year period), and a 2016
study found that "legalization would increase the economic
contribution of the unauthorized population by about 20%, to 3.6% of
private-sector GDP."

IMPACT ON THE SENDING COUNTRIES

Research suggests that migration is beneficial both to the receiving
and sending countries. According to one study, welfare increases in
both types of countries: "welfare impact of observed levels of
migration is substantial, at about 5% to 10% for the main receiving
countries and about 10% in countries with large incoming remittances".
According to
Branko Milanović , country of residency is by far the
most important determinant of global income inequality, which suggests
that the reduction in labor barriers would significantly reduce global
income inequality. A study of equivalent workers in the United
States and 42 developing countries found that "median wage gap for a
male, unskilled (9 years of schooling), 35 year-old, urban formal
sector worker born and educated in a developing country is P$15,400
per year at purchasing power parity". A 2014 survey of the existing
literature on emigration finds that a 10 percent emigrant supply shock
would increase wages in the sending country by 2-5.5%.

IMPACT ON GLOBAL POVERTY

According to economists
Michael Clemens and Lant Pratchett,
"permitting people to move from low-productivity places to
high-productivity places appears to be by far the most efficient
generalized policy tool, at the margin, for poverty reduction". A
successful two-year in situ anti-poverty program, for instance, helps
poor people make in a year what is the equivalent of working one day
in the developed world. Research on a migration lottery that allowed
that allowed Tongans to move to New Zealand found that the lottery
winners saw a 263% increase in income from migrating (after only one
year in New Zealand) relative to the unsuccessful lottery entrants. A
longer-term study on the Tongan lottery winners finds that they
"continue to earn almost 300 percent more than non-migrants, have
better mental health, live in households with more than 250 percent
higher expenditure, own more vehicles, and have more durable assets".
A conservative estimate of their lifetime gain to migration is
NZ$315,000 in net present value terms (approximately US$237,000). A
slight reduction in the barriers to labor mobility between the
developing and developed world would do more to reduce poverty in the
developing world than any remaining trade liberalization.

A 2017 study of European migrant workers in the UK shows that upon
accession to the EU, the migrant workers see a substantial positive
impact on their earnings. The data indicate that acquiring EU status
raises earnings for the workers by giving them the right to freely
change jobs.

INNOVATION AND ENTREPRENEURSHIP

According to one survey of the existing economic literature, "much of
the existing research points towards positive net contributions by
immigrant entrepreneurs." Areas where immigrant are more prevalent in
the
United States have substantially more innovation (as measured by
patenting and citations). Immigrants to the
United States create
businesses at higher rates than natives. A 2010 study showed "that a
1 percentage point increase in immigrant college graduates' population
share increases patents per capita by 9–18 percent." Mass migration
can also boost innovation and growth, as shown by the Huguenot
Diaspora in Prussia, German Jewish Émigrés in the US, the Mariel
boatlift, the exodus of Soviet Jews to Israel in the 1990s, European
migration to Argentina during the Age of Mass Migration (1850-1914),
and west-east migration in the wake of German reunification.
Immigrants have been linked to greater invention and innovation in the
US. According to one report, "immigrants have started more than half
(44 of 87) of America's startup companies valued at $1 billion dollars
or more and are key members of management or product development teams
in over 70 percent (62 of 87) of these companies." Research also
shows that labor migration increases human capital. Foreign
doctoral students are a major source of innovation in the American
economy. In the United States, immigrant workers hold a
disproportionate share of jobs in science, technology, engineering,
and math (STEM): "In 2013, foreign-born workers accounted for 19.2
percent of STEM workers with a bachelor's degree, 40.7 percent of
those with a master's degree, and more than half—54.5 percent—of
those with a Ph.D."

QUALITY OF INSTITUTIONS

A 2015 study finds "some evidence that larger immigrant population
shares (or inflows) yield positive impacts on institutional quality.
At a minimum, our results indicate that no negative impact on economic
freedom is associated with more immigration." Another study, looking
at the increase in Israel's population in the 1990s due to the
unrestricted immigration of Jews from the Soviet Union, finds that the
mass immigration did not undermine political institutions, and
substantially increased the quality of economic institutions. A 2017
study in the _
British Journal of Political Science _ argued that the
British American colonies without slavery adopted better democratic
institutions in order to attract migrant workers to their colonies.

WELFARE

Some research has found that as immigration and ethnic heterogeneity
increase, government funding of welfare and public support for welfare
decrease.
Ethnic nepotism may be an explanation for this phenomenon.
Other possible explanations include theories regarding in-group and
out-group effects and reciprocal altruism .

Research however also challenges the notion that ethnic heterogeneity
reduces public goods provision. Studies that find a negative
relationship between ethnic diversity and public goods provision often
fail to take into account that strong states were better at
assimilating minorities, thus decreasing diversity in the long run.
Ethnically diverse states today consequently tend to be weaker states.
Because most of the evidence on fractionalization comes from
sub-Saharan Africa and the United States, the generalizability of the
findings is questionable.

One study finds that non-native speakers of English in the UK have no
causal impact on the performance of other pupils. The presence of
immigrant children in classrooms has no significant impact on the test
scores of Dutch children. An Austrian study finds no effect on grade
repetition among native students exposed to migrant students. A North
Carolina study found that the presence of Latin American children in
schools had no significant negative effects on peers, but that
students with limited English skills had slight negative effects on
peers.

ASSIMILATION

A 2015 report by the National Institute of Demographic Studies finds
that an overwhelming majority of second-generation immigrants of all
origins in
France feel French, despite the persistent discrimination
in education, housing and employment that many of the minorities face.

A 2016 paper challenges the view that cultural differences are
necessarily an obstacle to long-run economic performance of migrants.
It finds that "first generation migrants seem to be less likely to
success the more culturally distant they are, but this effect vanishes
as time spent in the USA increases."

Research shows that country of origin matters for speed and depth of
immigrant assimilation but that there is considerable assimilation
overall. Research finds that first generation immigrants from
countries with less egalitarian gender cultures adopt gender values
more similar to natives over time. According to one study, "this
acculturation process is almost completed within one generational
succession: The gender attitudes of second generation immigrants are
difficult to distinguish from the attitudes of members of mainstream
society. This holds also for children born to immigrants from very
gender traditional cultures and for children born to less well
integrated immigrant families." Similar results are found on a study
of Turkish migrants to Western Europe. The assimilation on gender
attitudes has been observed in education, as one study finds "that the
female advantage in education observed among the majority population
is usually present among second-generation immigrants."

A 2017 study found that naturalization strongly improves long-term
social integration of immigrants: "The integration returns to
naturalization are larger for more marginalized immigrant groups and
when naturalization occurs earlier, rather than later in the residency
period."

First-generation immigrants tend to hold less accepting views of
homosexual lifestyles but opposition weakens with longer stays.
Second-generation immigrants are overall more accepting of homosexual
lifestyles, but the acculturation effect is weaker for Muslims and to
some extent, Eastern Orthodox migrants.

A study of Bangladeshi migrants in East
London found they shifted
towards the thinking styles of the wider non-migrant population in
just a single generation.

A study on
Germany found that foreign-born parents are more likely to
integrate if their children are entitled to German citizenship at
birth.
Naturalization is associated with large and persistent wage
gains for the naturalized citizens in most countries. One study of
Denmark found that providing immigrants with voting rights reduced
their crime rate.

Measuring assimilation can be difficult due to "ethnic attrition",
which refers to when ancestors of migrants cease to self-identify with
the nationality or ethnicity of their ancestors. This means that
successful cases of assimilation will be underestimated. Research
shows that ethnic attrition is sizable in Hispanic and Asian immigrant
groups in the United States. By taking account of ethnic attrition,
the assimilation rate of Hispanics in the
United States improves
significantly.

Studies on programs that randomly allocate refugee immigrants across
municipalities find that the assignment of neighborhood impacts
immigrant crime propensity, education and earnings.

Research suggests that bilingual schooling reduces barriers between
speakers from two different communities.

Research suggests that a vicious cycle of bigotry and isolation could
reduce assimilation and increase bigotry towards immigrants in the
long-term. For instance, University of California, San Diego political
scientist Claire Adida, Stanford University political scientist David
Laitin and Sorbonne University economist Marie-Anne Valfort argue
"fear-based policies that target groups of people according to their
religion or region of origin are counter-productive. Our own research,
which explains the failed integration of Muslim immigrants in France,
suggests that such policies can feed into a vicious cycle that damages
national security. French Islamophobia—a response to cultural
difference—has encouraged Muslim immigrants to withdraw from French
society, which then feeds back into French Islamophobia, thus further
exacerbating Muslims’ alienation, and so on. Indeed, the failure of
French security in 2015 was likely due to police tactics that
intimidated rather than welcomed the children of immigrants—an
approach that makes it hard to obtain crucial information from
community members about potential threats."

SOCIAL CAPITAL

There is some research that suggests that immigration adversely
affects social capital . One study, for instance, found that "larger
increases in US states' Mexican population shares correspond to larger
decreases in social capital over the period" 1986–2004.

HEALTH

Research suggests that immigration has positive effects on native
workers' health. As immigration rises, native workers are pushed into
less demanding jobs, which improves native workers' health outcomes.

HOUSING

A 2014 study of the
United Kingdom found that immigration generally
reduced house prices, because natives at the top of the wage
distribution respond to immigration by moving to other areas, reducing
demand for housing.

Much of the empirical research on the causal relationship between
immigration and crime has been limited due to weak instruments for
determining causality. According to one economist writing in 2014,
"while there have been many papers that document various correlations
between immigrants and crime for a range of countries and time
periods, most do not seriously address the issue of causality." The
problem with causality primarily revolves around the location of
immigrants being endogenous, which means that immigrants tend to
disproportionally locate in deprived areas where crime is higher
(because they cannot afford to stay in more expensive areas) or
because they tend to locate in areas where there is a large population
of residents of the same ethnic background. A burgeoning literature
relying on strong instruments provides mixed findings. As one
economist describes the existing literature in 2014, "most research
for the US indicates that if any, this association is negative...
while the results for Europe are mixed for property crime but no
association is found for violent crime". Another economist writing in
2014, describes how "the evidence, based on empirical studies of many
countries, indicates that there is no simple link between immigration
and crime, but legalizing the status of immigrants has beneficial
effects on crime rates."

The relationship between crime and the legal status of immigrants
remains understudied but studies on amnesty programs in the United
States and
Italy suggest that legal status can largely explain the
differences in crime between legal and illegal immigrants, most likely
because legal status leads to greater job market opportunities for the
immigrants. However, one study finds that the
Immigration Reform
and Control Act (IRCA) of 1986 led to an increase in crime among
previously undocumented immigrants.

DISCRIMINATION

EUROPE

Research suggests that police practices, such as racial profiling ,
over-policing in areas populated by minorities and in-group bias may
result in disproportionately high numbers of racial minorities among
crime suspects in Sweden, Italy, and England and Wales. Research
also suggests that there may be possible discrimination by the
judicial system, which contributes to a higher number of convictions
for racial minorities in Sweden, the Netherlands, Italy, Germany,
Denmark and France.

Several meta-analyses find extensive evidence of ethnic and racial
discrimination in hiring in the North-American and European labor
markets. A 2016 meta-analysis of 738 correspondence tests in 43
separate studies conducted in OECD countries between 1990 and 2015
finds that there is extensive racial discrimination in hiring
decisions in Europe and North-America. Equivalent minority candidates
need to send around 50% more applications to be invited for an
interview than majority candidates.

A 2014 meta-analysis found extensive evidence of racial and ethnic
discrimination in the housing market of several European countries.

THE UNITED STATES

Business

A 2014 meta-analysis of racial discrimination in product markets
found extensive evidence of minority applicants being quoted higher
prices for products. A 1995 study found that car dealers "quoted
significantly lower prices to white males than to black or female test
buyers using identical, scripted bargaining strategies." A 2013 study
found that eBay sellers of iPods received 21 percent more offers if a
white hand held the iPod in the photo than a black hand.

Criminal Justice System

Research suggests that police practices, such as racial profiling ,
over-policing in areas populated by minorities and in-group bias may
result in disproportionately high numbers of racial minorities among
crime suspects. Research also suggests that there may be possible
discrimination by the judicial system, which contributes to a higher
number of convictions for racial minorities. A 2012 study found
that "(i) juries formed from all-white jury pools convict black
defendants significantly (16 percentage points) more often than white
defendants, and (ii) this gap in conviction rates is entirely
eliminated when the jury pool includes at least one black member."
Research has found evidence of in-group bias, where "black (white)
juveniles who are randomly assigned to black (white) judges are more
likely to get incarcerated (as opposed to being placed on probation),
and they receive longer sentences."
In-group bias has also been
observed when it comes to traffic citations, as black and white cops
are more likely to cite out-groups.

Education

A 2015 study using correspondence tests "found that when considering
requests from prospective students seeking mentoring in the future,
faculty were significantly more responsive to White males than to all
other categories of students, collectively, particularly in
higher-paying disciplines and private institutions." Through
affirmative action, there is reason to believe that elite colleges
favor minority applicants.

Housing

A 2014 meta-analysis found extensive evidence of racial
discrimination in the American housing market . Minority applicants
for housing needed to make many more enquiries to view properties.
Geographical steering of African-Americans in US housing remained
significant. A 2003 study finds "evidence that agents interpret an
initial housing request as an indication of a customer's preferences,
but also are more likely to withhold a house from all customers when
it is in an integrated suburban neighborhood (redlining ). Moreover,
agents' marketing efforts increase with asking price for white, but
not for black, customers; blacks are more likely than whites to see
houses in suburban, integrated areas (steering ); and the houses
agents show are more likely to deviate from the initial request when
the customer is black than when the customer is white. These three
findings are consistent with the possibility that agents act upon the
belief that some types of transactions are relatively unlikely for
black customers (statistical discrimination)."

A report by the federal Department of Housing and Urban Development
where the department sent African-Americans and whites to look at
apartments found that African-Americans were shown fewer apartments to
rent and houses for sale.

Labor Market

Several meta-analyses find extensive evidence of ethnic and racial
discrimination in hiring in the American labor market. A 2016
meta-analysis of 738 correspondence tests - tests where identical CVs
for stereotypically black and white names were sent to employers - in
43 separate studies conducted in OECD countries between 1990 and 2015
finds that there is extensive racial discrimination in hiring
decisions in Europe and North-America. These correspondence tests
showed that equivalent minority candidates need to send around 50%
more applications to be invited for an interview than majority
candidates. A study that examine the job applications of actual
people provided with identical résumés and similar interview
training showed that African-American applicants with no criminal
record were offered jobs at a rate as low as white applicants who had
criminal records.

IMPACT ON THE SENDING COUNTRY

Remittances increase living standards in the country of origin.
Remittances are a large share of the GDP of many developing countries.
A study on remittances to Mexico found that remittances lead to a
substantial increase in the availability of public services in Mexico,
surpassing government spending in some localities.

Research finds that emigration and low migration barriers has net
positive effects on human capital formation in the sending countries.
This means that there is a "brain gain" instead of a "brain drain"
to emigration.

One study finds that sending countries benefit indirectly in the
long-run on the emigration of skilled workers because those skilled
workers are able to innovate more in developed countries, which the
sending countries are able to benefit on as a positive externality .
Greater emigration of skilled workers consequently leads to greater
economic growth and welfare improvements in the long-run. The
negative effects of high-skill emigration remain largely unfounded.
According to economist Michael Clemens, it has not been shown that
restrictions on high-skill emigration reduce shortages in the
countries of origin.

Research also suggests that emigration, remittances and return
migration can have a positive impact on political institutions and
democratization in the country of origin. Research also shows
that remittances can lower the risk of civil war in the country of
origin. Return migration from countries with liberal gender norms has
been associated with the transfer of liberal gender norms to the home
country.

Research suggests that emigration causes an increase in the wages of
those who remain in the country of origin. A 2014 survey of the
existing literature on emigration finds that a 10 percent emigrant
supply shock would increase wages in the sending country by 2-5.5%. A
study of emigration from Poland shows that it led to a slight increase
in wages for high- and medium-skilled workers for remaining Poles. A
2013 study finds that emigration from Eastern Europe after the 2004 EU
enlargement increased the wages of remaining young workers in the
country of origin by 6%, while it had no effect on the wages of old
workers. The wages of Lithuanian men increased as a result of post-EU
enlargement emigration. Return migration is associated with greater
household firm revenues.

Some research shows that the remittance effect is not strong enough
to make the remaining natives in countries with high emigration flows
better off.

It has been argued that high-skill emigration causes labor shortages
in the country of origin. This remains unsupported in the academic
literature though. According to economist Michael Clemens, it has not
been shown that restrictions on high-skill emigration reduce shortages
in the countries of origin.